1 files changed, 4 insertions, 0 deletions

diff --git a/arch/parisc/kernel/perf.c b/arch/parisc/kernel/perf.c
index 89d6d5ad44b5..f696f57faa15 100644
--- a/arch/parisc/kernel/perf.c
+++ b/arch/parisc/kernel/perf.c
@@ -46,6 +46,7 @@
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 #include <linux/miscdevice.h>
+#include <linux/smp_lock.h>
 #include <linux/spinlock.h>
 
 #include <asm/uaccess.h>
@@ -260,13 +261,16 @@ printk("Preparing to start counters\n");
  */
 static int perf_open(struct inode *inode, struct file *file)
 {
+        lock_kernel();
         spin_lock(&perf_lock);
         if (perf_enabled) {
                 spin_unlock(&perf_lock);
+                unlock_kernel();
                 return -EBUSY;
         }
         perf_enabled = 1;
         spin_unlock(&perf_lock);
+        unlock_kernel();
 
         return 0;
 }